Year	current US$
1999	24397547644.94155
2000	21340807650.385693
2001	21394264152.675224
2002	22353074915.418365
2003	25101582420.86038
2004	30618573370.006615
2005	35171910492.9447
2006	39069917902.53578
2007	44858753912.61131
2008	48555351906.592125
2009	45162344348.69953
2010	49594220873.8521
2011	54491094657.44685
2012	52292302311.4798
2013	53118103099.65502
2014	54396435415.31308
2015	49744163567.55475
2016	52240373751.11396
2017	57575295729.92994
2018	59668159877.037895
2019	59594952583.4531